Nonlinear BCJR equalizer for suppression of intrachannel nonlinearities in 40 Gb/s optical communications systems

作     者：Djordjevic, Ivan B. Vasic, Bane 

作者机构：Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA 

出 版 物：《OPTICS EXPRESS》 (Opt. Express)

年 卷 期：2006年第14卷第11期

页      面：4625-4635页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：.forward decoding correction constrained suppression nonlinearities OPTICAL COMMUNICATIONS decoder Intersymbol interference performance improvement trellis LDPC Intrachannel BCJR algorithm Nonlinear BCJR 

摘      要：A maximum a posteriori probability ( MAP) symbol decoding supplemented with iterative decoding is proposed as an effective mean for suppression of intrachannel nonlinearities. The MAP detector, based on Bahl-Cocke-Jelinek-Raviv algorithm, operates on the channel trellis, a dynamical model of intersymbol interference, and provides soft-decision outputs processed further in an iterative decoder. A dramatic performance improvement is demonstrated. The main reason is that the conventional maximum-likelihood sequence detector based on Viterbi algorithm provides hard-decision outputs only, hence preventing the soft iterative decoding. The proposed scheme operates very well in the presence of strong intrachannel intersymbol interference, when other advanced forward error correction schemes fail, and it is also suitable for 40 Gb/s upgrade over existing 10 Gb/s infrastructure. (c) 2006 Optical Society of America.